Method for forming article-holding display packages

ABSTRACT

The articles are enclosed in pockets, formed and sealed in plastic windows, of a foldable paperboard blank which has window openings on opposite sides of a fold line, the blank being covered on one surface by a heat-deformable and heat-sealable plastic sheet, at least over that area having the openings or windows formed therein. A blank support, a molding station and a blank discharge station are arranged along a linear blank travel path at substantially equal spacings from each other. A carrier is oscillatable in a vertical plane including the center line of the travel path, and carries air-released vacuum pick-up means at longitudinal spacings substantially equal to the spacings between the support and the stations. The carrier is oscillated between a first position and a second position. In the first position, a first vacuum pick-up means grips a blank on the support and a second vacuum pick-up means grips a blank, which has already been heated and has pockets formed therein, at the molding station. As the carrier is moved toward its second position, the blanks are lifted and the first pick-up means heats its supported blank. At the second position, the first pick-up means, which includes male die means, positions its blank over a female die means at the molding station, and the second pick-up means releases its formed blank at the discharge station. The already heated blank at the molding station is vacuum deformed into the female die to form the pockets, is released and the cycle is repeated. A dwell station preferably is positioned between the support and the molding station. An endless chain conveyor is moved past the discharge station and carries removable tables for receiving the formed blank. Articles are placed in the pockets at any point along the endless conveyor, and the blanks, during travel along the conveyor on the tables, are folded over to enclose the article and held in closed position while they are delivered to a turret which is revolved in synchronism with the movement of the endless chain and carries one or more, preferably three, piston and cylinder operated heat sealing dies for sealing the two halves of the blank to each other to seal the article in a pocket. The dies are supplied with dielectric energy only after engagement with the folded blanks. The packaged articles are then released onto a conveyor belt for transport away from the apparatus. The heating means for heating the blank preferably is mounted on the carrier, or may be positioned fixedly at a heating station.

This is a continuation, of application Ser. No. 437,314, filed Jan. 28,1974, now abandoned, which is a division of application Ser. No.205,817, filed Dec. 8, 1971, now U.S. Pat. No. 3,788,032.

FIELD OF THE INVENTION

This invention relates to the formation and sealing of article-holdingpockets in plastic windows of foldable paperboard blanks and, moreparticularly, to a novel, simplified, and more efficient method for thispurpose.

BACKGROUND OF THE INVENTION

It is known to seal articles in pockets which are formed and sealed inplastic windows of paperboard blanks. These blanks have one or moreopenings which are covered, on one surface, by a heat-deformable andheat-sealable plastic sheet. The pockets are formed by heating theplastic material extending across the windows and deforming this plasticmaterial to form a pocket. After the article is placed in the pocket,the pocket is closed, for example by folding the blank about a fold lineand then heat sealing the plastic material. As the plastic sheet or filmwhich is used is generally transparent, the article is provided in adecorative package in which it is sealed but nevertheless is fullyvisible.

However, while the known packaging machines for thus packaging articlesin transparent pockets in a paperboard blank provide a satisfactoryproduct, there has been a demand for a packaging apparatus, for formingsuch a product, which will be more efficient and have a much higheroutput per unit of time than machines and methods presently available.

SUMMARY OF THE INVENTION

In accordance with the invention, a packaging machine is provided whichis faster and more dependable than known packaging machines for formingand sealing article-holding pockets in plastic windows of foldedpaperboard blanks having window openings covered on one surface of theblanks by a heat-deformable and heat-sealable plastic sheet. While theinvention apparatus utilizes dielectric sealing, it effects continuousdielectric sealing with multiple electrodes. Thus, the inventionapparatus is at least twice as fast, or even faster, than knownapparatus of the same general class. For example, the production rate ofthe invention machine is at least 30 cycles per minute, as compared toknown machines, of the same general class, which have a production rateof 10 to 12 cycles per minute.

The method of the invention involves novel method steps which alsoresult in a greatly increased output per unit of time. The paperboardblank, in a starting state, is essentially a two-part blank having amedian fold line therein, and is formed with at least one pair of windowopenings, with the window openings of each pair being disposedsymmetrically on opposite sides of the fold line. That part of the blankwhich has the window openings or apertures therein, and whichconstitutes about one-half of the total blank area, has a sheet ofheat-deformable and heat-sealable plastic sealed to one surface. Inpracticing the method, the blank, having the sheet of plastic sealedthereto, is heated while it is being transported to a station where apocket is drawn in the heated plastic. After this, an article is placedin the formed pocket at a further station, following which the machinefolds the card over on itself so that the two halves are superposed withtheir plastic sheet coverings in superposed relation. The card is thenpassed to another station where the card is dielectrically heat sealedso that the article is completely enclosed in heat sealed plastic andmounted in the card or blank. The completed card then moves to anejection station or the like where it can be fed to a conveyor, bepackaged, or be subjected to whatever further processing may benecessary or desirable.

The apparatus includes a turret mounted for rotation about an uprightaxis and containing two or more heat sealing devices which are moved toand from work-engaging positions by fluid pressure actuators whoseoperation is controlled by valves operated by suitable cams. As eachheat-sealer moves into its operative position, it is automaticallyenergized from a dielectric generator. The heat sealers serve to sealthe folded over blanks to each other to enclose the article in a pocket,with the article being sealed in the pocket. The turret is rotated bysuitable drive mechanisms including a chain trained around a sprocketsecured to rotate with the turret.

An endless chain conveyor extends from the turret and is trained arounda sprocket rotatable with the turret, at one end, and around a returnsprocket spaced some distance from the turret. This endless chainconveyor has two parallel runs or strands. Blank support tables areremovably positioned on the endless chain conveyor to receive pre-formedblanks and to deliver these pre-formed blanks to the heat-sealing meansof the turret.

A blank forming line extends laterally from one run of the endless chainand has, at its outer end, a support table carrying a stack of thepaperboard blanks formed with the windows and having a sheet ofheat-deformable and heat-sealable plastic sealed to one surface andcovering the windows. At equal spacings from the table and from eachother, there are a dwell station, a molding or pocket forming station,and a discharge station which is at the run of the endless chainconveyor. A carrier is oscillatable in a vertical plane extendingthrough the center line of the path of travel from the support table tothe discharge station. This carrier is suspended by a pair of links andis oscillatable between two end positions. The carrier is provided withvacuum pick-up means, which are capable of being supplied with air underpressure for releasing an article. In one end position, one pick-upmeans on the carrier picks the top blank from the support table, anintermediate pick-up means picks up and heats a blank at the dwellstation and a third or other end pick-up means picks up a heated andformed blank at the molding or pocket forming station. In the other endposition, the first pick-up means transfers the blank picked up from thesupport table to the dwell station, the intermediate pick-up meanspositions the heated blank at the molding or pocket forming station, andthird pick-up means discharges a formed blank onto a support table onthe endless chain conveyor.

The formed blank is then moved along by the endless chain conveyor andan article may be dropped into the already formed pocket therein at anypoint. As the formed blank moves onto the other parallel run of theendless chain conveyor, folding means cooperate with the blank to foldthe blank about its median fold line and to retain the blank in foldedcondition. The thus folded blank is then moved into operative relationwith one heat-sealing means on the turret and, during continued rotationof the turret, is heat-sealed to sealingly enclose the article in aplastic pocket. After leaving the heat-sealing turret, the completedpackaged article is dropped onto an endless belt conveyor extendingsubstantially centrally and longitudinally of the device between the twoparallel runs of the endless chain conveyor.

Mechanical interconnections are provided between the carrier for thepick-up means, the turret, the heat-sealing means, and other elements sothat all elements of the machine operate in synchronized relation. Dueto the multiple dielectric sealing heads on the turret, which arecontinuously operated, the output of the apparatus per unit of the timeis very substantially increased. As stated, the output is of the orderof 30 cycles per minute or better, as compared to an output of 10 to 12cycles per minute of known apparatus of the same general class or type.

An object of the invention is to provide an improved method for formingand sealing article-holding pockets in plastic windows in paperboardblanks having window openings covered, on one surface of the blanks, bya heat-deformable and heat-sealable plastic sheet.

A further object of the invention is to provide such a method which ischaracterized by an output, per unit of time, which is verysubstantially in excess of the output, per unit of time, of knownmethods and apparatus for performing essentially the same operation.

Another object of the invention is to provide such a method utilizingcontinuously operable heat-sealing means.

For an understanding of the principles of the invention, reference ismade to the following description of typical embodiments thereof asillustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a side elevation view of one form of packaging apparatusembodying the invention;

FIG. 2 is a perspective view of the paperboard blank in its initialcondition;

FIG. 3 is a perspective view of the completed article;

FIG. 4 is a top plan view of the apparatus, corresponding to FIG. 1;

FIG. 5 is a transverse sectional view taken on the line 5--5 of FIG. 4;

FIG. 6 is a view, similar to FIG. 5, but illustrating a carrier in adifferent position;

FIG. 7 is an enlarged vertical sectional view of a blank positioned on aresilient pad at the dwell station;

FIG. 8 is an enlarged vertical sectional view showing a heated dieholding the blank in position over the mold at a molding station;

FIG. 9 is a still further enlarged vertical sectional view of the heateddie member illustrating the vacuum connection for holding and carrying ablank;

FIG. 10 is a view taken on the line 10--10 of FIG. 9;

FIG. 11 is an enlarged vertical sectional view of the female dieillustrating its vacuum connection and the actual formation of a pocket;

FIG. 12 is a view taken on the line 12--12 of FIG. 11;

FIG. 13 is an enlarged partial side elevation view, corresponding toFIG. 1, illustrating support tables on one of the runs of the conveyorand moving toward the blank folding mechanism;

FIG. 14 is a similar view illustrating a phase of the folding operation;

FIG. 15 is a similar view illustrating the final phase of the foldingoperation;

FIG. 16 is a vertical sectional view on the line 16--16 of FIG. 6,illustrating the removable connection of a support table to the endlessconveyor;

FIG. 17 is an enlarged plan view of the turret and heat sealing area,corresponding generally to the line 17--17 of FIG. 1;

FIG. 18 is a partial sectional view taken on the line 18--18 of FIG. 19;

FIGS. 19 and 19a, when combined one above the other, constitute avertical sectional view on the line 19--19 of FIG. 17;

FIG. 20 is an enlarged vertical sectional view illustrating the sealingoperation being performed by dielectric sealing electrodes;

FIG. 21 is a horizontal sectional view taken along the line 21--of FIG.1 and illustrating the drive mechanism of the apparatus;

FIGS. 22, 23, 24 and 25 are views taken along the correspondinglynumbered lines of FIG. 21 and illustrating respective cams of theapparatus;

FIG. 26 is a partial side elevation view of a modified form of transfermechanism;

FIG. 27 is a view similar to FIG. 26 illustrating another modified formof the apparatus; and

FIG. 28 is a schematic diagram of the air and vacuum lines and controlsof the apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 through 4 of the drawing, the apparatus embodyingthe invention, and which is generally illustrated, in elevation, in FIG.1 and, in plan, in FIG. 4, is arranged to form substantially flat blanks10, such as shown in FIG. 2, into display packages 10', such as shown inFIG. 3. Each blank 1 includes a sheet of paperboard 11 having a medianfold line 12 and formed with pairs of apertures 13, preferably circularin form, with the respective apertures of each pair being disposed onopposite sides of fold line 12 and at substantially equal distancestherefrom. At least that portion of paperboard base 11 formed with theapertures 13 has a sheet 14 of heat-deformable and heat-sealable plasticsealed thereto, as by heat sealing. In the operation of the machine, theplastic windows covering the apertures 13 are heated and then deformedto form pockets, after which articles are placed in these pockets andthe blank 10 is folded about its median fold line 12 to enclose thearticles. Finally, the folded blank, particularly that portion havingthe pockets therein, is heat-sealed to form the pockets 15, eachcontaining an article to be displayed, as shown in FIG. 3. While theapertures 13 are illustrated as circular, they can be any desired shapein accordance with the shape of the article to be enclosed in theresultant plastic window pockets 15, and the articles may be eithercontained loosely in the sealed plastic window pockets or may beconformingly retained therein by heat-sealing the plastic materialaround the articles.

The apparatus comprises a main frame, generally indicated at 20, whichsupports the blank folding means, the heat sealing means, a dischargeconveyor, and the drive means of the apparatus. A side frame 25 extendslaterally from main frame 20, so that the apparatus, in plan, has agenerally T-shape, and side frame 25 carries means supporting a stack ofblanks 10, as well as supporting a dwell station, molding station andtransfer means for picking blanks 10 from the stack and moving themsuccessively to the dwell station, to the molding station and to adischarge station on the main frame 20.

Main frame 20 includes a generally horizontal upper member 21, which maybe termed a table, supported by legs 22, and includes an intermediatehorizontal member 23 which supports the driving means for the apparatus.Side frame 25 has an upper generally horizontal element 26 supporting adwell station and a molding station, member 26 being supported bygenerally upright legs such as 27. For a purpose to be described, aframework 28, forming part of the side frame 25, extends above themember 26. The frame 25 is illustrated in considerable detail in FIGS.4, 5 and 6. At the outer end of frame 25, or to the left thereof asviewed in FIGS. 5 and 6, a shelf 31 supported on legs 27 serves as asupport for a blank support table 30 on which there is arranged a stackof blanks 10. Table 30, whose height is adjustable by means of a fluidpressure actuator generally indicated at 32, is guided for verticaladjustment by a guide generally indicated at 33 and cooperating, in itsguiding function, with the actuator 32. Table 30 constantly supplies astack of blanks 10 at a constant level, and air jet means, describedmore fully hereinafter, direct a separation air jet at the stack ofblanks at the proper moment to separate the top blank from the nextlower so that the top blank may be picked up. Fluid pressure actuator 32is controlled by a sensing means to maintain table 30 at the properheight.

Referring more particularly to FIGS. 5 through 12, the blanks 10 arepicked up from the stack on table 30, transferred to a dwell station,then transferred to a molding station, and then discharged by transfermeans including a carrier 35 comprising a pair of generally trapezoidalcentrally apertured vertically oriented plates 35A and 35B. At itsopposite upper corners, carrier 35 is pivotally connected to the freeends of respective links 36 whose opposite ends are secured torespective shafts 34 oscillatably mounted in respective bearings 37secured to the undersurface of the upper horizontal element 38 offramework 28, the arrangement being such that carrier 35 is spacedlaterally from upper element 38, as will be seen in FIG. 4. Carrier 35is arranged to be oscillated from the position shown in FIG. 5 to thatshown in FIG. 6, by oscillation of links 36. In moving from the positionshown in FIG. 5 to that shown in FIG. 6, links 36 are pivoted clockwiseto swing upwardly and to the right, as viewed in FIG. 5, and upon returnfrom the position shown in FIG. 6 to that shown in FIG. 5, links 36 arepivoted upwrdly and counterclockwise to the position shown in FIG. 5.The arrangement constitutes a parallel motion linkage, so that carrier35 is always maintained with its lower edge substantially horizontal.

Respective pick-up devices 40A and 40B are secured to the opposite lowercorners of carrier 35, each pick-up device including a bracket 41,welded or otherwise secured to carrier 35, and a substantiallyhorizontal plate 42 welded or otherwise secured to a respective bracket41. Each plate 41 carries a plurality of vacuum cups 43A, 43B which maybe connected either to a source of vacuum or to a source of air underpressure.

Intermediate the length of carrier 35, a bracket 44 secured to its loweredge supports a combination heater, male die and pick-up elementgenerally indicated at 45 and shown more clearly in FIGS. 7, 8, 9 and10. Heater element 45 includes a substantially horizontal plate 46secured to bracket 44 and connected by legs 47 to a lower plate 48. Avacuum cup 51 is secured to upper plate 46 and extends downwardlythrough a notch in the end of plate 48 so that its vacuum cup portion ispositioned below plate 48. Vacuum cup 51 is arranged to be selectivelyconnected to a source of vacuum or to a source of air under pressure.

An electrically energized heater 50 is mounted in heat conductingrelation on plate 48 substantially centrally with respect to a pair ofmale dies 55, there being as many pairs of male dies 55 as there aretransparent plastic pockets to be formed in a blank 10. As best seen inFIGS. 9 and 10, each male die has a circular configuration correspondingto the circular configuration of a pocket in blank 10, and is generallyH-shape in cross section including an annular rim 52 and a circular web53 formed with a series, such as four, of apertures 54 arranged atequiangular spacings. Web 53 is spaced from plate 48 to define a vacuumchamber 56, as shown in FIG. 9, and with each vacuum chamber 56communicating with a conduit 57 which may be selectively connectedeither to a source of vacuum or to a source of air under pressure.Conduit 57 has as many branches extending through apertures in plate 48as there are male dies 55. The vacuum supplied through conduit 57, incooperation with the vacuum supplied to cups 51, serves to maintain ablank 10 in engagement with the combination heater and die element 45.

It should be noted that the elements 40A, 45 and 40B have equal centerto center spacings from each other, and these center to center spacingsare equal to the center to center spacings of a dwell station, a femalemold, and a discharge station on the main frame 20. The dwell station 60is adjacent blank supply table 30, and comprises a plate 61 adjustablysupported by threaded legs 62, a layer of rubber 63 being secured to theupper surface of plate 61, as best seen in FIG. 7.

Following dwell station 60 there is a mold station at which there is afemale mold 65 best seen in FIGS. 5, 6, 11 and 12. Female mold 65 has amold cavity 64 conforming to the shape of the plastic pocket to beformed in blank 10. For the purpose of drawing the heated plastic film14 into mold cavity 64 to form the pocket 15, mold cavity 64 has itsgenerally flat bottom surface formed with intersecting channels orgrooves 66 which communicate, at their intersection, with a bore 67which may be selectively connected to a source of vacuum, bore 67extending from cavity 64 through the female mold 65. In forming thepocket 15, each female mold cavity 64 cooperates with a respective maledie 55 which has already imparted a relatively shallow concave shape tothe plastic film 14 at each of the apertures 13. However, the actualcompletion of the formation of each pocket 15 is effected by supplyingvacuum through line 67 to the interior of mold cavity 66 to draw theheated plastic into the mold cavity 64 so that the plastic assumes theshape of the mold cavity 64. The end result of this operation isindicated more particularly in FIG. 11.

As stated, carrier 35 is oscillatable between a first position, shown inFIG. 5, at which pick-up element 40A is at table 30, heater element 45is at dwell station 60 and pick-up element 40B is at the female mold 65,to a second position, shown in FIG. 6, in which pick-up element 40A isat dwell station 60, heater element 45 is at female mold 65, and pick-upelement 40B is at the discharge station, which latter is described morefully hereinafter. To effect this oscillatory movement of carrier 35,with the carrier maintaining a constant horizontal orientation,respective sprockets 71 are secured to shafts 34 and are engaged with anendless chain 72 whose lower end is engaged with a relatively largesprocket 73. Sprocket 73 is secured to a shaft 74 which is oscillated bymeans of a crank arm 70 secured thereto and having its outer endpivotally connected to a connecting link 76 whose opposite end ispivotally secured to an eccentric pin 77 on a crank 75 secured to rotatewith a shaft 78. As crank 75 rotates, it oscillates sprocket 73 throughlink 76 and crank arm 70 to oscillate carrier 35 between its two extremepositions.

The discharge, or blank-deposit, stations are constituted by supporttables 80 removeably mounted at spaced intervals on an endless chain 85trained around sprockets 86A and 86B adjacent opposite ends of mainframe table 21. Sprockets 86A and 86B are rotatable about substantiallyvertical axes, and sprocket 86B is driven in a manner describedhereinafter, with sprocket 86A being driven from sprocket 86B by chain85.

As best seen in FIGS. 5, 6 and 12 through 15, support tables 80 havepins 81 projecting from their upper surfaces and arranged to properlyposition a blank 10 on the support table, the particular layout, inplan, of pins 81 depending on the particular configuration of blanks 10.For a purpose to be described, each support plate 80 is furtherprovided, adjacent its leading edge in the direction of travel of chain85, with additional pins 82 whose height is somewhat less than theheight of pins 81, which are headed at their upper ends. For readyreference, the additional pins 82 will be hereinafter referred to as thedeflecting pins. Support tables 80 comprise substantially flat metalplates which are releasably secured by screws to the upper peripheraledges of rectangular buckets 83, so that support tables 80 are elevatedabove the level of chain 85. Within the area defined by the locatingpins 81, each support plate has an aperture 84 to receive the pockets 15on the blanks 10, so that these pockets project downwardly into theassociated bucket 83. The buckets are made sufficiently deep toaccommodate all depths of pockets 15.

Support plates 80 may be readily interchanged to handle blanks ofdifferent shapes and with different dimensions of pockets, by simplyremoving the holding screws and placing another support plate on abucket 83. In addition, the entire assembly including the support table80 and the bucket 83 is readily removable from chain 85 as illustratedin FIG. 16. From FIG. 16, it will be noted that, at intervalstherealong, chain 85 is provided with upwardly projecting spaced pins87, one of which projects into a mating aperture in the base 88 of abucket 83 and the other of which projects into a slot in the base 88 ofthe bucket. Thus, the assemblies can be readily removed by merelylifting the tables 80 secured by screws to the buckets 83, such removalof the buckets themselves, however, being necessary only for inspection,maintenance or repair.

The blanks 10, having the pockets 15 formed therein, are deposited bycarrier 35 on the support tables 80, and travel to the left, as viewedin FIG. 4, with the tables moving around the sprocket 86A, and spaced atregular intervals along chain 85. In the opposite straight run of chain85, the blanks 10 carried by the support tables 80 are folded about themedian fold lines 12. This operation is illustrated more particularly inFIGS. 13, 14 and 15. Referring to FIG. 13, a blank 10 deposited on asupport table 80 is positioned by the locating pins 81, but its forwardor leading edge rests on the deflecting pins 82 so that the blank isarched somewhat upwardly. As each support table 80, having a thusupwardly arched blank 10 mounted thereon, moves along the straight runof chain 85 from the position shown at the left in FIG. 13 to theposition shown at the right, cam fingers 90, secured to an oscillatableshaft 91 to which is also secured a spring finger 92 projecting fromshaft 91 in a direction nearly opposite to the direction of projectionof cam fingers 90. The three cam fingers 90 slide beneath theundersurface of blank 10.

Referring to FIG. 14, at a position upstream or in advance of the camfingers 90 there are three hold-down fingers 95, which are springfingers secured to oscillate with a shaft 93. Shaft 93 has securedthereto, as best seen in FIG. 1, an arm 94 whose free end is articulatedto the outer end of the piston rod 97 of a pneumatic actuator 96. Thepiston of actuator 96 is spring biased upwardly to move arm 94 to theposition shown in FIG. 1, and the piston is moved downwardly by airpressure. When air is supplied to the piston of actuator 96, piston rod97 is retracted downwardly and arm 94 is pivoted clockwise. This causesthe spring hold-down fingers 95 to engage blank 10 with wheir free edgesengaging the blank at the median fold line 12. This position is shown inFIG. 14. As the support table 80 continues to move to the right, asshown in FIGS. 14 and 15, cam fingers 90 fold the blank 10 about themedian fold line 12, with the blank 10 being held by the holddownfingers 95 at this median fold line, so that the cam fingers 90 now rideon the outer surface of the folded blank 10, as viewed in FIG. 15.Immediately after the position shown in FIG. 14 is reached, air pressureis released from acutator 96 so that fingers 95 are swung upwardly outof action. The cam fingers 90 now hold the blank 10 in folded conditionon support table 80, as viewed in FIG. 15 and, as the support table 80continues to move to the right, the spring finger 92 secured to shaft 91engages the folded blank and maintains the blank folded as the blank istransported to the heat sealing turret 100 which is concentric with thesprocket 86B.

From FIGS. 5 and 6, it will be noted that each bucket 83, adjacent itsnormally outer edge, is provided with a depending support leg or guide98 having a flat lower surface. During passage along the straight runsof conveyor chain 85, bottom wall or base 88 and depending guide 98 ofeach bucket 83 engage respective brass rails 101A and 101B mounted onrespective supports 102A and 102B. The brass rails 101 provided for easysliding movement of the buckets when traveling along the straight runsof conveyor chain 85. As the support tables 80 enter the range ofsprocket 86B and heat sealing turret 100, the support tables aresupported very accurately and steadily on a flat annular turret shelf103 to which sprocket 86B is bolted or otherwise secured. At the heatsealing turret, base 88 engages a flat arcuate brass rail 104A securedto the upper surface of sprocket 86B, and guide 98 engages a flatarcuate brass rail 104B secured directly to shelf 103. The rails 104Aand 104B provide for easy sliding movement of the buckets 83 as thesetends to oscillate in a horizontal plane while passing around sprocket86B and around heat sealing turret 100. This is particularly importantwhen the heat sealing dies are pressed downwardly against the foldedblanks 10 on the support tables and, to insure accurate horizontalorientation of each support table, the brass rails 104 may be shimmed soas to provide a perfectly level support surface for the buckets 83.

Shelf 103 is formed as a flange on the upper end of a tubular centralmember 105 which is rotatably supported at its lower end in axiallyspaced bearings 106 in a tubular column 107 supported on lower shelf 23of main frame 20. The shelf is reinforced by trapezoidal flanges 108which are arranged in pairs to extend from central member 105, the pairsof webs being arranged in equiangular relation to each other, as bestseen in FIG. 21. Just above the upper end of tubular column 107, asprocket 110 is secured to an L-shaped flange 111 on member 105, as bestseen in FIG. 19a.

A second tubular member 112, somewhat larger in diameter than tubularmember 105, is bolted to turret shelf 103 to extend upwardly therefromcoaxially with tubular member 105. An enlarged diameter flat cup-shapedportion 113 is formed on the upper end of member 112, and member 112 hasa shoulder 114 at its juncture with portion 113 and which seats anannular plate 116. The upper end of cup-shaped member 113 has anoutwardly projecting hexagonal flange or shelf 115 having threerelatively short edges 117 and three relatively long edges 118. Ininwardly spaced substantially parallel relation with each shorter edge117, a wall 121 extends upwardly from shelf 115, and walls 121 areinterconnected by walls 122 each extending inwardly spaced parallelrelation to a longer side 118. Adjacent each wall 121, flange or shelf115 has an outwardly opening notch receiving the cylinder 123 of arespective pneumatic actuator 120 having a vertically oriented pistonrod 124 to the lower end of which is secured a respective heat sealingdie generally indicated at 125. The sealed enclosure 126, laterallydefined by the walls 121 and 122, is closed at the top by a plate 127seated in shoulders formed adjacent the upper edges of walls 121 and122, and a circular plate 128 is disengageably secured to the upperedges of these walls in vertically spaced relation to the plates 127.

The supply of air to the actuators 120, and the exhaust of airtherefrom, is effected through a rotary union 130 mounted on the plate128 and connected to the actuators through respective cam actuatedvalves 131. An angular support arm 132 is secured to main frame 20, andextends across turret 100 at a distance above plate 128. Conduit means133 extend along arm 132 and are connected, at the free end of the arm,to the rotary union 130. Arm 132, which is fixed against rotation,supports a fixed arcuate cam 135 which cooperates with respectiveactuators 134 at the inner end of each valve 131, cam 135 beingangularly oriented and fixed so as to operate valves 131 in the correctsequence and for the correct period of time during the heat sealingoperation. To maintain the proper angular orientation of the sealingdies 125 secured to pistons 124, each piston has connected thereto aguide rod 136 vertically reciprocable between spaced rollers 137 on theupper end of the associated cylinder 123. For this purpose, the pistonrod 124 of each actuator 120 extends through both opposite ends of theassociated cylinder 123.

The sealed enclosure 126 protects against radiation during heat sealingof the blanks, and each sealing die, when engaged with a folded blank10, also forms a sealed enclosure therewith, to protect radiation. Theelectrical connections from a dielectric generator 140 to the sealingdies 125 are also sealed against radiation. These various means will nowbe described.

Each dielectric heater sealer comprises a support plate 141 secured tothe lower ends of the associated piston rod 124 and supporting, throughinsulators 142, an electrically conductive plate 143 carrying heatsealing electrodes 144 engageable with the folded blank supported on atable 80, as best seen in FIG. 20. A sealing wall 146 depends from eachelectrically conductive plate 143 and completely encloses the electrodesconnected thereto, this sealing wall having brush lower edges engageablewith the support table 80 to form a sealed enclosure. Grounding iseffected by spring fingers 147 which engage the support table 80 whichis in electrical contact with the brass supports 104 in turn connectedto the main frame 20.

A tube 145 has its upper end secured in the opening in plate 115 andextends coaxially downwardly through tubular members 112 and 105 withits lower end secured by a clamp 148 to a plate 151 secured by suitablesupports 152 to shelf 23 of main frame 20. The conductor tube 145 isaligned with an aperture 153 in plate 151, and the space beneath plate151 is enclosed by a sealing enclosure 154 secured to dielectricgenerator 140. A main conductor 150 is mounted coaxially of tube 145 bymeans of upper and lower insulators 154. Main conductor 150 projects, atboth ends, outwardly of the adjacent insulator 154. The lower end ofconductor 150 is connected to a conductor strap or bus bar 156 supportedon an insulator 157 and electrically connected to the output conductor158 of dielectric generator 140. As shown more particularly in FIG. 18,the contact sector 155, of electrically conductive material, is securedto the upper end of main conductor 150, which is also of electricallyconductive material.

Contact sector 155 serves to supply dielectric current from dielectricgenerator 140 to heat sealing dies 125 during the period when each heatsealing die is to effect a heat sealing of a folded blank. For thispurpose, each heat sealing die has a relatively rigid conductor 160electrically connected and secured at its lower end to the conductiveplate 143. Each conductor 160 extends upwardly through a respectivesealing tube 161 secured to the associated support plate 141 andextending upwardly through an aperture in the lower wall of cup 113.Each conductor 160 is supported in an insulator 162 in the upper end ofits associated tube 161. An arm 163 is adjustably secured to the upperend of each conductor 160 to extend radially inwardly, and the radiallyinner end of each arm 163 carries a brush 164. As each heat sealing die125 is lowered by its actuator 120 to the heat sealing position, asillustrated at the right in FIG. 19, its associated brush 164 engagescontact sector 155 to energize the heat sealing electrodes 144. In orderfor such energization to occur, the respective heat sealing die 125 mustbe within the sector, considered in the direction of rotation of theheat sealing turret, in which heat sealing takes place, this sectorbeing indicated by the dot and dash lines in FIG. 17, with the lowerline being indicated "start of seal" and the upper line being indicated"end of seal". As a heat sealing unit enters this sector, the actuator134 of the associated valve 131 engages the cam 135 to effect operationof the associated actuator 120 to lower the heat sealing die into theposition shown at the right in FIG. 19. At the end of the sector, theassociated brush 164 disengages contact sector 155 to disconnectdielectric generator 140 and, shortly thereafter, actuator 134 of theassociated valve 131 disengages cam 135 so that actuator 120 is operatedto lift the sealing die 125 to the position shown at the left in FIG.19.

Each heat sealing unit is also provided with a switch cam 165 cooperablewith a switch 166 to energize dielectric generator 140 as the heatsealing unit reaches the heat sealing zone. Plate 143 also carriesvacuum pick-up cups 167 arranged to pick-up and transport a heat sealedblank 10 following the heat sealing operation and as the associatedactuator 120 is moved to the upper position. The vacuum connected tocups 167 is released as each heat sealing unit reaches a position abovean endless carrier 170, shown in FIGS. 1 and 4, to drop the heat sealedarticle 10' onto endless conveyor 170 for transport to a furtherstation. Conveyor 170 is driven separately from the rest of theapparatus.

FIG. 21 illustrates the driving means of the apparatus, and FIGS. 22-25illustrate the operation of various cams for controlling operation ofthe apparatus. FIG. 21 is a horizontal sectional view on the line 21--21of FIG. 1. Referring to FIGS. 21, a motor 168 drives a right anglereduction gear 171 through a variable pulley and belt drive 172, and achain 173 drivingly interconnects the output sprocket of reduction gear171 to a sprocket 174 secured on a main shaft 175 rotatably supported ingearings 176 on frame 20. Crank 75, driving connecting rod or link 76,is secured to rotate with shaft 175 at one end thereof to oscillate thecarrier 35 through oscillation of shaft 74. A second sprocket 177secured to rotate with main shaft 175 is connected by a chain 178 to asprocket 181 on a cam shaft 180, supported in bearings 182, of whichonly one is shown in FIG. 21.

A spur gear 183 on the other end of main drive shaft 175 meshes with aninput spur gear 184 of a right angle gear box 185 having a verticallyoriented output shaft 186 to which is secured a sprocket 187 connectedby a chain 188 to sprocket 110 secured to rotatable member 105 of theheat sealing turret 100. All of the mechanism of the apparatus is drivenfrom the described driving means, except discharge conveyor 170, whichis separately and externally driven. At the left end of FIG. 21, theremay be seen the guided support for the blank supply table 30.

Cams 190A-190D are secured to rotate with cam shaft 180 and operatevarious control valves 195A-195D, as shown in FIGS. 22-25. FIG. 22illustrates cam 190A controlling operation of valve 195A which controlsthe connection of the source of vacuum to the mold and vacuum pick-upsof the transfer or carrier mechanism shown in FIGS. 5 and 6. Cam 190B,as shown in FIG. 23, operates a control valve 195B which controls thesupply of air for the jet for separating the top blank 10, on supporttable 30, from the blank immediately beneath the top blank. As shown inFIG. 24, cam 190C operates a valve 195C for controlling the supply ofair under pressure to the pick-up cups of the transfer mechanism. InFIG. 25, cam 190D is illustrated as operating a valve 195D whichcontrols supply of air to the actuator 96 for operating the blankfolding fingers 95. The interconnections of these valves in the air andvacuum circuits will be described more fully with reference to FIG. 28.

FIG. 26 illustrates a modified form of transfer mechanism wherein theheating is effected at the second position, by a heater 50', during theinterval a blank 10 is at this second station, the member 45'constituting, in this instance, only the male member of the mold and notincluding the heater. However, while an arrangement of this type workssatisfactorily, it is nowheres near as efficient or satisfactory as thearrangement shown in FIGS. 1 through 25 and 28, wherein the blank isheated as it is being transported from the second station to the thirdstation and while it is at both of these stations. In the arrangementshown in FIG. 26, heater 50' is stationary, and carrier 35 mounts anunheated male die having the same vacuum provisions as described inconnection with FIGS. 5 through 10.

In the modified embodiment of the invention shown in FIG. 27, onetransfer position is eliminated, and the heated male die member 45 picksup a blank 10 directly from the supply stack and heats the blank whiletransferring it to the position at which the female mold 65 is located.The blank has its pockets formed at the female mold and is thendelivered to a support table 80.

FIG. 28 schematically illustrates the pressure air lines and the vacuumlines and their connections to the various valves and to the operatedelements. Referring to FIG. 28, an air line 191, connected to a sourceof air under pressure, has included therein the usual filter 192,pressure regulator 193 and lubricating device 194. A line 196, connectedto air line 191, supplies air under pressure to valve 195B, operated bycam 190B, and controlling the supply of air to an air jet nozzle 200arranged at blank support table 80 to direct an air jet separating thetopmost blank 10 from the blank 10 immediately beneath the topmostblank. A line 197, branched from line 196, supplies air to a solenoidoperated valve 198 controlling the supply of air under pressure to thefluid pressure actuators 120 for the heat sealing dies on turret 100. Apressure responsive switch 201 is connected in series in a line 202extending from solenoid operated valve 198 and allows operation ofdielectric generator 140 if the pressure in line 202 is sufficient foroperation of the fluid pressure actuators 120. From switch 201, the airis supplied to the rotary union 130 at the upper end of the turret, andfrom the turret 130, air is supplied slowly through a restricted orifice203 to an air pilot 204 for a valve 205. When valve 205 is activated byits air pilot 204, it provides air to the individual valves 131,operated by cam 135, controlling operation of each pneumatic actuator120. The lower ends of the fluid pressure actuator cylinders aresupplied with air, from rotary union 130, through a reducing valve 206,to bias the pistons of the fluid pressure actuators to their upperpositions. The individual valves 131, which are operated by cam 135selectively, supply high pressure air to the upper surfaces of thepistons to move the pistons down to the sealing position.

A line 197 supplies air from line 191 to valve 195D operated by cam 190Dand controlling the supply of air to the spring biased fluid actuator 96controlling the blank folding fingers 95. A regulating valve 208 isconnected to air line 197 and supplies air to a manually operated valve200 controlling the supply of air to an air-oil diaphragm cylinder 211having the piston rod 32 connected at its upper end to support table 80for the blanks 10. When in the illustrated right hand position, valve200 effects lowering of support table 80 and, when valve 200 is moved tothe left position, the stack of blanks would rise to its proper level.However, none of this operation will occur unless a solenoid operatedvalve 202, interposed between cylinder 211 and the hydraulic pressure ofaccumulator 203, is not activated, to allow oil to flow from cylinder201 to accumulator 203, and vice versa. Below its connection toregulating valve 208, as illustrated in FIG. 28, line 197 is connectedto valve 195C operated by cam 190C, and this valve controls a supply ofair pressure to the pick-up cups of the transfer mechanism so that thesecups drop off a card after vacuum has been supplied and then cut off. Tothe right of valve 195C, there is illustrated valve 195A, operated bycam 190A, which, in the illustrated position, supplies vacuum to thepick-up cups of the transfer mechanism. In the opposite position fromthat illustrated, valve 195A vents the vacuum cups. The vacuum issupplied through a line 215 connected to valve 195A. A solenoid operatedvalve 213 above valve 195A cuts off either vacuum or air pressure fromthe last set of suction cups so that no cards will be dilivered to asupport table 80 unless valve 213 is energized. Vacuum line 215 is alsoconnected, through a rotary valve 214, to the vacuum cups 167 on theheat sealing dies. The timing of rotary valve 214 is such that completedarticles 10' will be carried to and dropped onto discharge conveyor 170for discharge from the machine.

While it is believed that the operation of the machine will be clearfrom the foregoing description, it is desired to emphasize an importantfeature of the apparatus which is the heating of the blanks 10 duringtransfer from support table 30, or from an idling station, to the femalemold. This particular provision of the method of the invention differssubstantially from prior art arrangements in which the cards are heatedat one station, either after delivery thereto followed by molding, orare heated only after being delivered to the mold. This enormouslyincreases the output per unit time of the apparatus. Further outstandingfeatures of the invention include the various control means foreffecting a rapid and accurately timed sequence of operations of theforming and packaging apparatus. The enclosed arrangement for the supplyof the dielectric energy from dielectric generator 140 to the heatsealing dies 125, and which prevents radiation to the exterior, alsoconstitutes a very important feature of the invention.

Summarizing briefly, the individual blanks 10 are picked up from supporttable 11, and transferred step by step to the support tables 80, theindividual blanks being heated during transfer from a support surface toa female mold. The molded blanks are then delivered from the female moldto the support tables on the chain conveyor and, while traveling aroundthe chain conveyor, are folded about a median line and held folded whilethey are passed to the heating dies which complete the heat sealingoperation. The heat sealing operation, which is conducted in acompletely shielded manner, is followed by delivery of the completedarticles 10' to the discharge conveyor 170. While the invention has beenillustrated as applied to blanks having only two windows for formingpockets, it should be understood that the blanks may have only onewindow or as many or these windows as necessary or desirable.

Although the same has not been shown or described, means can readily beprovided to prevent delivery of a blank to selected support tables 30,so that these support tables would reach the heat sealing turret 100without any blanks thereon. This would enable operation of the machinewith less than the full number of heat sealing units. In the particularexample shown in the drawings, the machine can be operated with eitherone, two or all three heat sealing units, on turret 100, operative, orwith one or two heat sealing units being inoperative.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:
 1. In a method for forming and sealing articleholding pockets in plastic windows in a series of sheet-like blankmembers, each member having at least one window opening covered on onesurface by a heat formable, heat sealable plastic sheet sealed to saidone surface, wherein heat is applied to the plastic sheet and then, at amolding station, pressure is applied to the already heated plastic sheetto cause the plastic sheet to conform to the shape of a female mold andform a pocket, then an article is inserted into the pocket, the said atleast one window opening of said blank is superimposed with a furtherblank member to enclose the article within the pocket and the blanksections are sealed to each other by the application of heat andpressure, the improvement comprising: transporting each blank from asupply station to the molding station and partially forming said packetby heating the plastic sheets covering said at least one window openingof each blank to the molding temperature during said transporting bydirect thermal contact of said plastic sheet and a heated die memberunder differential air pressure, drawing said thus heated plastic sheetthrough said window opening into a female mold to complete forming ofsaid pocket, transferring said blank to an article insertion station andinserting an article in said pocket, superimposing said blank with afurther blank section, sealing said further blank section to said heatsealable plastic sheet by the application of heat and pressure at asealing station, and wherein a different blank is operated upon at eachstation.
 2. The method of forming and sealing article holding pockets ofclaim 1, further comprising the step of transporting each blank from thesupply station to the molding station by said heated male die memberprovided with blank pick-up and release means utilizing the heated maledie means to position the heated blank in operative relation with saidfemale mold at the molding station; and applying a vacuum to the femalemold means to draw heated plastic windows thereinto to form pockets.